Create Class Hierarchy YAML

The current docs/output/structure.json file is too large and inefficient for AI agent consumption. To provide a lean but effective overview of the project's class structure, we will create a new build artifact.

Goal

Modify the buildScripts/docs/jsdocx.mjs script to generate a new file at docs/output/class-hierarchy.yaml.

Requirements:

1. Format: The file must be in YAML.
2. Content: It will contain a simple key-value mapping of className: parentClassName.
3. Sorting: The entries must be sorted alphabetically by the className (the key).
4. Implementation: This will be done within the existing jsdocx.mjs script, leveraging the already-parsed documentation data.
5. Agent Integration: Update AGENTS.md to instruct the agent to parse docs/output/class-hierarchy.yaml instead of the old structure.json file.